<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .outer{
            width: 1000px;
            height: 600px;
            background-color: #888888;
            margin: 0 auto;
            display: flex; 
            justify-content: space-between;
            flex-direction: column;
            /* align-items: flex-end; */
            /* align-items: center; */


        }
        .innner{
            /* width: 200px; */
            background-color: skyblue;
            border: 1px solid black;
            box-sizing: border-box;
        }
        .inner1{
            /* width: 300px;
            height: 400px; */
        }
        .innner2{
            /* height: 300px; */
        }
        .inner3{
            /* height: 100px; */
            /* width: 200px; */
        }
    </style>
</head>
<body>
<div class="outer">
    <div class="innner inner1">1</div>
    <div class="innner innner2">2</div>
    <div class="innner inner3">3</div>
</div>
</body>
</html>